245/253, .660/.660 in 496?

[Brian Callahan]

Anyone run this solid roller or something similar in a 496? Say 10.2:1 compression and heads that flow about 375 CFM intake @ .600". What's it like? Street manners? Idle quality? Performance? How many miles would it last?

245°/253° @ .050, .660/.660 lift, 112° lobe separation

[CarNDrvr]

That's actually pretty mild. I had a 10.8:1 496 with AFR's that flowed in the 360ish range. I had a comp 254/260, 660/660, 110lsa cam in it and it was very streetable.

[LILRED496]

Originally Posted by Brian Callahan

Anyone run this solid roller or something similar in a 496? Say 10.2:1 compression and heads that flow about 375 CFM intake @ .600". What's it like? Street manners? Idle quality? Performance? How many miles would it last?

245°/253° @ .050, .660/.660 lift, 112° lobe separation

I'm running a similar grind in my 496 its hydraulic its street friendly.
252@50 660/660 111 lobe sep

[Brian Callahan]

Lilred, that combo you have seems to run the number. What are the rest of your specs, compression in particular? What idle speed and vacuum do you get in and out of neutral?

CarNdrvr, what's your idea of mild? Like, what idle vacuum did your combo have and what sort of stall speed and gears did it need? On the flip side, what top end rpm would it pull to?

[Doug Jaynes]

even the high dollar Jessel solid rollers will need to be inspected and possibly swapped out every season if this sees much street use. that will be a pretty mild cam in that size engine, Id look at a hyd roller or even a flat tappet cam and not worry about lifter failure .

food for thought

Doug

[LILRED496]

Originally Posted by Brian Callahan

Lilred, that combo you have seems to run the number. What are the rest of your specs, compression in particular? What idle speed and vacuum do you get in and out of

496,flatops,zero deck, 113 cc heads cut.050,9.7.1comp
It idles about 700 Ive never done any vacuum tests. My power brakes work good with this cam.
we did a pumpgas 534 with a hydraulic cam that went 9s.
Ive seen street bbc with solids and the lifters and springs were toast in 5,000 miles.If you stay under 6500 run a hydraulic your not gonna miss the 7 hp at peak

[CarNDrvr]

I never checked vacuum at idle, but my power brakes worked fine idling at 850rpm. I had a 4000 stall and 3.73 gears. This was a street/strip combo, so I wanted that much stall. It pulled to 6500 easily. Old School's 496 has 262/266@.050, .680/.680, 110lsa. He drives it on pump gas and runs mid 6's with 4.10's and a 4500 stall.

[TooLateVTEC]

That cam is way mild for a 496...streetability wouldnt be a concern at all with the right converter/gear combo.

[scrapmetal]

Originally Posted by TooLateVTEC

That cam is way mild for a 496...streetability wouldnt be a concern at all with the right converter/gear combo.

times two

[Brian Callahan]

5000 miles is a lot for this car. Still a concern?

Define your idea of "streetable". Good idle quality would be nice.

6800 rpm in 3rd gear is 123 mph. That's about the trap speed we're hoping for.

[Brian Callahan]

LOL!

Throw some quantities out, here. Like, what idle vacuum or what minimum rpm where it stops acting like a wet rag before you consider it "streetable"? There is not a consensus among us Camaro types.

Right now we have a 246°/246°/.623/.623 solid roller in the engine, which used to be 460 in³. When we stroked it from 460 to 496 (8% more swept volume), the improvement to the idle quality was not noticeable.

[450bench]

Brian, I run a cam very similar to the one you have which I got from Chet Herbert...Mine is cut on a 108 and I put it in on a 106...It's in a 461 and I like it a lot...Great cam

[sami]

hi brian,

i have a similar LUN solid roller cam (0.660 0.660) on 489 but LSA/ICL: 110/104

10.75:1 comp + gm heads some port and polish..1000cfm holley

i have been driving more than 2000miles .if you dont mind on gas .no problem on high way ..for street manners you are over 1700rpm nop


i used isky solid roller with 112 not aggresive as lunati ..no problem in city driving with tremec 600

and 3.7 rear and 285-40-17 tires



how LUN idle and burnout

http://videos.streetfire.net/video/P...aro_208174.htm


regards
sami

Originally Posted by Brian Callahan

Anyone run this solid roller or something similar in a 496? Say 10.2:1 compression and heads that flow about 375 CFM intake @ .600". What's it like? Street manners? Idle quality? Performance? How many miles would it last?

245°/253° @ .050, .660/.660 lift, 112° lobe separation

[79ZED]

Brian,

Isn't this cam going in your EFI BBC? if so, you can ran a way bigger cam and still keep good driveablity, run all your accessories, and have a wide powerband to boot. All depends on your engine combo, heads, compression , and induction and what you want out of it. If you have a good flowing set of aftermarket heads and the compression to support it, a bigger cam could give you a stronger, wider power curve with little loss in low speed torque. With a 496 end EFI, the torque is just a squeeze of the throttle away.

I originally spec'd a 248/252 @ 0.05 and 708/708 lift for my 509 build but I realized rather quickly after talking to guys over at team Chevelle, I was leaving a lot on the table with that cam. I have AFR 315 CNC heads on the 509 along with a Holley EFI with a 2000 cfm TB and 60 lb injectors. Dual wideband. So, I was lucky enough to get hold of Harold Brookshire ( UDHarold) the cam designer who owned Ultradyne, and made cams for Comp ( HE series) and Lunati ( Voodoo ). We went over my specs and my intended purpose: nearly all street but has to run A/C and other power accessories. T56 with 3:73 gears. harold was a great guy to talk to, I spent nearly 3/4 hr talking about cams with him! He said he would work on it a get back to me. Here's what he came up with ;

289/295, 258/264, 180/185 on 112, advanced 4. Lift was up to me, so I went with a something that would take advantage of the heads even though it will mean more maintenance. I ended up with 730/730" net, this is with 1.75 Jesel rockers, so I guess you could also add a touch to the above duration figures as well. Solid roller cam and I'm sure it will run great when it's back on the road this Summer.
Just a thought, and good luck with your build.

John

[69CHVL]

Good thread, let me add my experiences. I have a 454HO/AFR305's. Ran a 231/239 .600 Voodoo HR, idles a 800, 11-12" of vac, real nice cam, lugs down to 1200 in overdive. Changed out that cam for a Comp 245/252 .650 110lsa HR, idles at 1000, vacuum in 8-9" fully warmed up, brakes are marginal AFTER the motor is warmed up. But, it idles pretty much the same, and drives the same. Doesnt like to go below 1500, and is really happy at 2000 for cruising, and will pull 6500rpms. Now, this cam is based on the Magnum lobes (real slow, long seat timing). I would imagine any more modern grinds with less seat timing (this has an adv dur of ~306/314) will idle even better and make more vacuum.

Now, I'm building a 509 BB, and went with the tried-and-true XR286 248/254, as I know this cam has put many a heavy Chevelles in the 10's, and has proven to be a very reliable cam (not killing lifters and springs), but always wondered if I should go a little more, like a 254/260. But the OD trans is a factor in my decision. But sometimes, you just have to do your homework, install the cam, and see whatcha got. If you have to go up or down a size so be it.

Dont know of any of you guys saw that recent BBC alum head test in one of the rags. They took a 8.75:1 502 and added a set of alum heads, and a "small" 245/250 .650 SR, almost all the heads were making like like 650+HP, just about 600ft/lbs. I'm pretty much modeling my build after this, except for a couple more cubes, a point more compression, and a lightly larger cam. Hope to "hit" their #'s, maybe a bit better.